Telegraph system.



l. H. BELL.

TELEGRAPH SYSTEM.

APPLICATION FrLED MAY I6. 191e.

Patented Apr. L 19l9.

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unifinn s'ra'ins PATENT OFFICE.

JOHN H. BELL, OF EAST ORANGE, NEW J E COMPANY, INCORPORATED, OF NEW YORK,

TLEGRAPH SYSTEM.

Application led May 16,

iii telegraph systems, and more particularly ,f to improvements in equipment whereby an Figu operator who may be receiving a message is enabled to signal orinterrupt an operator who may be sending such message. In teleaph workin such operations are coinmbnly termed break or breaking servicc, and are frequently found necessary in the handling of telegraphic communications, all as well understood in the art.'

The principal object of this invention is to provide an im roved and simpliied equipment for enabling break operations to be performed in connection with telegraph working over lines consisting of a single section, or overlines comprising a plurality of sections, in which interworking is accomplished by means -ofsuitable repeating equipments.

' In accordancewith this invention, and in addition to equipmenty for the usual interchange of message impulse signals, a line relay and a local circuit relay are provided for each line circuit at terminal'stations, and a line relay for each line is also'provided at repeating stations for transmitting or receiving break service impulse signals. The relays for break service are adapted to remain inert under currents of such strength as sufiice for the transmission of telegraphic signals. When it is-desired to` interrupt 'a sending station, however, a break key 1s operated at a receiving station, thereby causing currents of greater 'strength to flow through the various circuits to operate the break relays, and the contacts of such a relay at the station which may be :sending serves to disconnect the transmitting devices thereat.

This invention is illustrated cally .in the accompanying drawing, in which re 1 illustrates an equipment suitable for a telegraph terminal station, and Fig. 2 illustrates an equipment. suitable for a telegraph repeating station.

The features of this invention may be diagrammati Specification oi? Letters Patent.

Patented Apr. 1,1919.

191e. seriaiimsmsi.

readily understood from a description of the operation of the system. Therefore, the

various steps by which telegraphic signals may be transmitted, received and interruplted by breaking at a station receiving w1 now be described.

Referring to Fig. 1 of the drawing, let it be assumed that this terminal station equipment is typical'of an equipment at a distant station (not shown), connected in a similar manner to a main line circuit or section indicated by the reference character 1. Let it be further assumed that a signal transmitting key 18 is being operated to send a message to the distant station. At each closure of the key 18, a'circuit is established which may be traced from a grounded Ibattery 6, the contacts of a relay 7, thence through the serially connected windings of relays 8,

11, 14, a sounder 17 the key 18 and a resistance unitj19 to the earth connection. The

current through this circuit is of suflicient strength to operate the relays 11 and14 and the sounder 17 ,but owing to the presence of. the resistance unit 19, it is not strong enough to operate the break relay 8. Therefore, at each closure of the key 18, a circuit is completed from a grounded source of negative current, indicated by the conventional sign,

,over the contacts 16 of the relay 14, the contacts 13 of the relay 11, the winding of the relay 7the contacts 9 of the relay 8, from, which point it reaches the distant station by way of the line conductor 1. The equipment at the distant station corresponds with the equipment at. the station shown. Therefore, at that point, the impulse of negative' current continues overa circuit corresponding to the contacts 9 of the' relay 8, the winding of the relay 7 the cont-acts 12 of the relay 11, and the winding of a polarizedrelay 2Oz to the earth connection. The result of this current action at the distant station corresponds with the operation of the relayz 20 to close its contacts 21, and thereby include a source of current 22 to operate la receiving sounder 23. The relay adapted to release slowly. Therefore, during the periods the key 18 is open in thel sending processes, the relay 11 remains operated to continuously maintain its 'contacts 13 closed: while under such open moments at the key 18, the transmitting relay 14 re- 14' is adapted to operate quickly and to release quickly; while@ the relay 11, although operating quickly, is

sponse of the polarized relay 20 and the re sulting operation of the sounder 23, that this message is being received at the station shown. Assuming that the operator at the last mentioned station desires to instantly -attract the attention of the sending operator in order, say to request that a letter or Word be repeated, the receiving operator depresses a break key 25. This key completes the same circuit already described as controlled by the key 18, except that the resistance unit 19 is not at this time included.` The omission of the resistance 19 accordingly reducesthe resistance of the circuit through the relays 8, 11, 14 and the sounder 17, whereupon the resulting increase in current from the bat tery 6 causes the operation of the marginally, adjusted relay 8; the separation .of the contacts 9 of this relay disconnects the receiving relay 20, and the closing of its contacts 10 connects a source of grounded positive current, indicated by the conventional sign and of relatively high potcntial, with the lino `circuit, 1. At the distant station, which is assumed to be sending at this time, current' from the high pressure source completes circuit over a path which, for convenience, may be considered as corresponding u'ithjhe contacts 9 of the relay 8, the winding of the relay 7, the contacts l13 of the relay 11, thence to the two-Way contacting armature of a transmitting relay 14, thence to earth through either the positive orthe negative source of grounded current; according to the position of the armature of the relay 14. With respect to its lcontacts 15 or 16'at the instantl the` break current arrives. The voltage of the positive break current source is sufiiciently high, even in case it is opposed' by the regular positive signaling current at the distant or sending station.tocause a current 'of such strength to fiow through the marginally adjusted break relay, corresponding to the relay 7, to cause its operation for disconnecting a local transmitting circuit corresponding with the battery 6.

the relays 8, 11 and 14the sounder 17, the key 18 and the resistance unit 19. Cessation of action in the sending sounder at the distance station constitutes an indication or notice that the station receiving desires to send, which operatlon may take place in the usual Way after the first' sending operator has released the transmitting key.

In adapting this break service for usc in connection with line circuits operating 'through repeating equipments, a clear understanding of such a system may be had by assuming that the line circuit of the terminal station set shown in Fig. 1 is connected with a line conductor 2 of the repeating set shown in Fig. 2, while the line circuit3 of this repeating set may be assumed as extending to a distant station (not shown at which the terminal equipment corresponds with that shown'in the Figi 1, and the conduc-tor 3 is thereat connected; to a line cir- 8o cuit conductor corresponding with the line l. Sign-als transmitted from the station (Fig. 1) reach the repeating equipment over the line conductors 1 and 2, thence continuing over the contacts 31 ot' a break relay 30, a conductor 34, the Winding of a mar inally adjust-ed break relay 36, which Winding is, for convenience" of adjustment, shunted by a resistance unit`39, the contacts 41 of a relay 40, a conductor'43, thel Winding of a quick operating, slow-releasing universal current relay -45 and the windings of a polarized relay 48 to an earth connection. In response to the alternate changes of'current polarity set up by the transmitting relay 14, under control of the sending key 18, the polar relay 48 selectively moves its l'armature to correspondingly' include the associated grounded sources of positive and negative current to complete a circuit, "which may be traced 100 from the armature of this lpolar relay 48, the contacts 47 of the relay 45, the winding of 'a marginallv ladjusted break relay 30 (the wainding of this relay is for convenience of adjustment, shunted byl a resistance unit 33) 105 "1a conductor 35, the contacts 37 of the relay 36 to the linecircuit 3, over which it reaches the distant station and is received by means of a polar relay and sounder, lrespectively corresponding with E20 and 23 of Fig. 1. In 110 a converse manner, messages transmitted in the opposite direction, that is, from the distant station to the station Fig. 1, set up current impulses which reach the repeating equipment \over the line circuit 3, thence traversing the contacts 37 of thev relay 36, a conductor 35, the winding of the relay 30, the contacts 4G of the relay 45, a conductor 44, the winding of the quickloperating slowrelease universal current relay 40, and the windings of a polarized relay 52, to an earth connection. .Changes of current direction, as set up through the polarized relay 52 by the message impulses transmitted from the distant station, cause this relay to respond thereto, and alternately connect the associated grounded sources of positive and negative current to the varmature of this rela-y. F romv this armature, these current impulses traverse the contacts 42 of the relay 40, the 130r winding of the relay 36, the conductor '34, the contacts 31 of the relay 30, thence overthe main line conductors 2 and 1 to the receiving circuit already traced at ,the first station, Fig. l, at which point the polarized relay 20 operates the sounder 23 to reproduce the message. Assuming now that this station, Frig. 1, desires to attract the attention of the distant sending operator, the break key25 is depressed to operate the marginally adjusted relay 8, which thereupon switches the line l from the receiving circuit to the high potential source of break current. This break current then traverses the line conductors 1 and 2, the contacts 31 of the relay 30, the conductor 34, the Winding of the relay 36, the contacts 42.of the relay 40 (this relay is operated at this time, due to message impulses from the distant station), thence to the armature of the polar relay 52, 'from which point, the break current. completes circuit to earth through either one of the associated grounded sourcesot` signaling current, according to the position of this polarized armature at the inst-ant the break current arrives. justed relay 3G receives a-suflicient wattage from the break current to cause. it to operate, thereby switching the line circuit 3 from the repeater equipment at the separa-ted contacts 37. and, through the contacts 38, connects this line circuit directly to a grounded source of high potential positive break-current, indicated by a conventional sign at this relay. This repeated break current reaches the distant station'by way of the line circuit 3, and thereat operates a relay corresponding with the relay 7 to disconnect the local transmitting devices, as already described for single section Working. The op erations at the repeating stat-ion which take place when the distant station interrupts a message, being transmitted from the station (Fig. 1), are set up by the high potential break current from the line 3 traversing the contacts 37 of the relay 36, the conductor 35, the Winding of the break relay 30, the contacts 47 of the relay 45, (this relay is held operated at this time by Vmessage impulses from the station, Fig. 1), to the armature of the polar relay 48, from which point the circuit is ,completed through the associated source of signaling current with which this armature may at the moment be connected. The resulting incremented currentthrough the relay 30 'causes it to operate, and' through the' separation of its contacts 31 and the closingof its contacts 32,'respectively, switches the line conductor 2 from the repeating equipment and connects it directly to a grounded source of highpotential break current, suitably indicated at this relay. From this point, the break current reaches the station (Fig. l) by way of conductors 2 and' 1,

and operates the relay 7 to disconnect the The marginally ad# transmitting devices as already described for single Section Working.

From the foregoing` description, it will be apparent that, on a single section two-Way telegraph line, the marginal local circuit relay 8, under control of the break key 215, controls a distant marginally adjusted line relay 7, to disable the sending equipment at such distant station. And also that in the repeating equipment, While the relays 45 and 48 comprise a group for repeating message signals from the line 2 into the line 3, the marginally adjusted line relay 36 serves to repeat high potential break currents from the line 2 into the line 3, and conversely, the line relays 40 and 52 at the repeating station operate to repeat message signals from the line 3 into the line 2, While the marginally adjusted line relay 30 operates to repeat high-potential break currents from the. line 3 into the line 2.

Referring to my pending application, Serial No. G3251, filed Nov. 24, 1915, for a telegraph system, it will be understood that the terminal station or repeating station equipments therein disclosed may be used interchangeably with the equipments disclosed in the present application. From the descriptions already made in connection with .these applications, the operations and actions taking place with interchanged ai'- rangements for working the equipments of the two systems would be readily apparent to a person skilled in the art. Therefore, it is considered that descriptions of such proposed working are accordingly unnecessary.

lVhat is claimed is 1,

1. In a telegraph system, a transmitting apparatus, a line associated therewith, a source of normal operating current, a source of abnormal operating current, a relay in circuit with said transmitter, said relay being responsive only to abnormal current, circuit breaking means between said line and said sources of current and controlled by said relay, and means for impressing abnormal current on said relay to operate said current breaking means and put abndrmal current on the line.

2. In a telegraph system, a transmitter, a receiver, and a line, a relay in said transmitter responsive .to abnormal current, means in said line controlled by said relay, to put abnormal current on said line, a relay in said line. responsive to abnormal current, means in said transmitter controlled by said last mentioned relay to open the circuit of said transmitter.

3. In a telegraph system, means for transmitting and receiving telegraphic. messages,

means in circuit therewith for repeating said messages, local and line relays coperating with said repeating means, said relays being with said repeating means, means controlled by said relays for simultaneously opening the circuit to said repeatin .means and for impressing said break service current on a line, and means for controlling said relays to operate said relay with said control means. p

4. In a telegraph system, a line, a transmittel', a receiver, and repeating stations connected therewith, a plurality of current.

sources at each station, means responsive to operating current to impress said current sources on the line, a source of bre`s'a.kserviceV current at each station, switching means adapted to put said break service current on -15 the line, means at each station responsive to abnormal current to operate said'switching means, and means for controlling said switch operating means.

In witness whereof, I hereunto subscribe 20 lmy name this 12th day of May, A. D., A1916.

JOHN H. BELL. 

